n this paper a novel implementation of the adaptive controllers designed by the use
of Robust Fixed Point Transformation
is studied. Instead guaranteeing global stability the
so designed controllers work smoothly in a bounded region
of operation. Both the limits of this region as well as the
performance of the controller depends on the basic component
of the RFPT-based design, i.e. on the properties of a sigmoid
function that can be defined in various manners. In this case
a special, easily parameterizable sigmoid was chosen that is
widely used in the daily engineering practice, a truncated linear function. This function
has a single parameter, its slope, that +in the same time determines the width of
the window within which the adaptive nature of the controller is guaranteed. It was
found that by varying this parameter either the precision of the controller or the
frequency of the necessary adaptive tuning can be improved. This statement is substantiated
by simulations.
